A hearing aid is an electro-acoustic device which is designed to amplify sound for the wearer, usually with the aim of making speech more intelligible, and to correct impaired hearing as measured by audiometry. There are many types of hearing aids (also known as hearing instruments) such as BTE (Behind The Ear), ITE (In The Ear), CIC (Completely In the Canal), RIC (Receiver In the Canal), and the like.
Among them, a hearing aid of the RIC type has a structure that a receiver is inserted in the ear. Normally the RIC hearing aid is composed of a receiver, a hardware module, a case for covering the hardware module, and an interface unit for connecting the receiver and the case. Such RIC hearing aids are often classified into an integrated style in which the receiver and the hardware module are united together, and a connected style in which the receiver and the hardware module are separable from each other. A hearing aid of the connected style further requires another interface unit for connecting the receiver and the hardware module.
When a hearing aid of the integrated style, even though only one of both the receiver and the hardware module is damaged, it may not be possible to replace only the defective with a new one. This is inefficient.
When a hearing aid of the connected style, a connecting part between the receiver and the hardware is prone to damage. For example, if a user applies much excessive force or tries to connect in a wrong direction, the connecting part is easily damaged.